如何在

Question

为什么我不能指定ES的值？我的值是.5，13和2，尽管没有从2中得到任何结果，但这是错误

在打印("Allowance =")中，ES NameError: name 'ES‘未定义

import math

D = input("Nominal Size: ")
TPI = input("TPI: ")
TOL = input("Tolerance Class 1, 2, 3: ")
P = float(1.0/TPI)
H = float((math.sqrt(3)/2)*P)
D2 = float(D-2*.375*H)
D1 = float(D-2*.625*H)


if ((0.05*(pow(P,2)**(1/3))+(0.03*(P/D)))-0.002) < (0.25*P)-(0.4*pow(P,2)):
    ES = float((0.25*P)-(0.4*pow(P,2)))

print ""
print ("Pitch ="), P
print ("Fundamental Triangle Height ="), H
print ("Allowance ="), ES
print ("Basic Pitch Diameter ="), D2
print ("Basic Minor Diameter ="), D1

Answer 1

只有在无法穿透的条件下才设置ES：

((0.05*(pow(P,2)**(1/3))+(0.03*(P/D)))-0.002) < (0.25*P)-(0.4*pow(P,2))

是真的。显然不是。

如果ES存在合适的默认值，您可以预先设置它，或者在else子句中设置：

ES = 0    # whatever default is valid
if ((0.05*(pow(P,2)**(1/3))+(0.03*(P/D)))-0.002) < (0.25*P)-(0.4*pow(P,2)):
    ES = float((0.25*P)-(0.4*pow(P,2)))

或

if ((0.05*(pow(P,2)**(1/3))+(0.03*(P/D)))-0.002) < (0.25*P)-(0.4*pow(P,2)):
    ES = float((0.25*P)-(0.4*pow(P,2)))
else:
    ES = 0    # whatever default is valid

如果没有合适的默认值，则可以将ES初始化/设置为None，然后在打印时显式检查：

print ("Allowance ="), ES if ES is not None else '?'

(或者'None'实际上是一种合理的打印方式)

Answer 2

只需在要使用的相同范围上分配默认值即可。如果条件不计算为true，则将打印0。

ES = 0
if ((0.05*(pow(P,2)**(1/3))+(0.03*(P/D)))-0.002) < (0.25*P)-(0.4*pow(P,2)):
    ES = float((0.25*P)-(0.4*pow(P,2)))

print ES

Answer 3

好吧，我弄明白了。谢谢你们。我正在做，提升到权力，而不是把它提升到一个权力，这使我搞砸了，我从1/3改为.333333，我添加了ES，改为TD1，在if语句之上。我加上了P1，做了一个指数，然后它变成了if，作为它的一半，然后再提高它。对于那些没被抓到的人，我对蟒蛇很陌生。这是计算螺纹直径大调和螺距大调。

import math

D = input("Nominal Size: ")                  ##Nominal thread size
TPI = input("TPI: ")                         ##Thread per inch
TOL = input("Tolerance Class 1, 2, 3: ")     ##Class 1A 2A 3A 1B 2B 3B
P = float(1.0/TPI)                           ##Thread pitch
H = float((math.sqrt(3)/2)*P)                ##Height of fundamental triangle
D2 = float(D-2*.375*H)                       ##Thread basic pitch diameter
D1 = float(D-2*.625*H)                       ##Thread basic minor diameter
P1 = pow(P,2)                                ##Lots of exponent stuff
SDT = .54127*P                               ##Single depth of threads
DDT = SDT*2                                  ##Double depth of threads
MiMDI = D-DDT                                ##Minimum Minor Diameter Internal
MiPDI = (D-(0.32475953*P)*2)                 ##Minimum Pitch Diameter Internal
ES = 0                                       ##Allowance
Td = 0                                       ##Major diameter tolerance of external threads
Td2 = 0                                      ##Pitch diameter tolerance of external threads
TD1 = 0                                      ##Minor diameter tolerance of internal threads
TD2 = 0                                      ##Pitch diameter tolerance of internal threads

if ((0.05*pow(P1,.33333333333)+(0.03*(P/D)))-0.002) < (0.25*P)-(0.4*pow(P,2)):
    TD1 = float((0.25*P)-(0.4*pow(P,2)))

MaMDI = MiMDI+TD1                                ##Maximum Minor Diameter Internal

print ""
print ("Pitch ="), P
print ("Fundamental Triangle Height ="), H
print ("Allowance ="), ES
print ("Basic Pitch Diameter ="), D2
print ("Basic Minor Diameter ="), D1
print ""
print ("INTERNAL THREADS")
print ("MINIMUM Minor Diameter ="), MiMDI
print ("MAXIMUM Minor Diameter ="), MaMDI
print ("MINIMUM Pitch Diameter ="), MiPDI
##print ("MINIMUM Pitch Diameter ="), MaPDI